AB0821 The frequency of lumbosacral transitional vertebras in patients with ankylosing spondylitis
Authors: N. Gokcen, O. Ozdemir Isik, A. Yazici, A. Cefle
Journal: Annals of the Rheumatic Diseases (2022)

Background Lumbosacral transitional vertebras (LSTVs) are anatomic variations observed at L5-S1 junction (1). The prevalence of LSVT ranges from 3.9% to 35.6%, indicating that this congenital anomaly is common in general population. LSVTs are well-defined anatomical differences causing low back pain and pelvic trauma (2). However, the studies assessing the influence of abnormal lumbosacral anatomy on low back pain and sacroiliac joints in patients with ankylosing spondylitis (AS) are scarce (3). Objectives The current study aimed to investigate the frequency of LSVTs and the their effects on clinical variables in AS patients. Methods The study was designed as a prospective cross-sectional study. 113 patients were included in the study. Demographic data, clinical variables, laboratory results were recorded. Disease activity (ASDAS-CRP and ASDAS-ESR), patients’ functionality (BASFI, BASMI), enthesitis (Leeds enthesitis index) and quality of life (SF-36, visual analogue scale) were evaluated. The baseline pelvic conventional radiographs and the sacroiliac magnetic resonance imaginings at the diagnosis were screened and assessed by two independent physicians. LSTVs were classified via Castellvi classification. Kappa coefficient was used to find the interobserver reliability. Results LSVTs were observed in 38 (33.6%) patients. Castellvi type Ia, Ib, IIa, IIb, IIIa, IIIb, and IV were found in 10 (8.8%), 7 (6.2%), 7 (6.2%), 6 (5.3%), 4 (3.5%), 1 (0.9%), and 3 (2.7%) patients, respectively. The kappa value for interobserver reliability was 0.69. There were not any differences between AS patients with and without LSVTs in terms of disease activity, functionality, and quality of life (Table 1). No statistically significant correlation was found between LSVTs identified by conventional radiography and sacroiliitis determined by MRI. When compared the patients according to Castellvi classification, visual analogue scale was higher in patients with IIIa than in patients with IV (p=0.013). Disease duration was longer in patients with Ib than in patients with Ia (p=0.029). ASDAS-CRP and ASDAS-ESR were higher in patients with IIIa than in patients with IV (p=0.008 and p=0.007). Table 1. The comparison of clinical characteristics between patients with and without LSVTs Patients without LSVTs (n=75 ) Patients with LSVTs (n=38 ) p VAS 3.0 (2.0−5.0) 3.4 (1.0−6.0) 0.734 Disease duration (month) 122.0 (60.0−180.0) 120.0 (57.0−183.0) 0.834 ASDAS-CRP 1.8 (1.2−2.5) 1.8 (1.2−2.9) 0.855 ASDAS-ESR 1.6 (1.2−2.5) 1.6 (1.0−2.7) 0.976 CRP 1.8 (0.8−5.3) 2.5 (1.0−6.1) 0.471 BASMI 2.9 (2.0−4.4) 3.0 (2.1−4.0) 0.796 BASFI 1.8 (0.7−4.6) 2.1 (0.7−3.0) 0.768 SF-36 Physical function 80.0 (55.0−95.0) 80.0 (63.8−95.0) 0.765 Role physical 45.6 (0−100.0) 50.0 (25.0−100.0) 0.280 Role emotional 66.7 (0−100.0) 33.0 (0−100.0) 0.267 Energy/fatigue 50.0 (35.0−70.0) 60.0 (38.8−71.3) 0.201 Mental health 64.0 (48.0−76.0) 68.0 (52.0−80.0) 0.330 Social functioning 62.5 (50.0−87.5) 75.0 (50.0−100.0) 0.252 Body pain 67.5 (45.0−80.0) 67.5 (45.0−90.0) 0.751 General health 45.0 (35.0−65.0) 50.0 (40.0−71.3) 0.411 Values are given as median (interquartile range) Conclusion In AS patients, the frequency of LSVT is 33.6%, which is consistent with the general population. Type I, also known as a dysplastic transverse process, is the most observed type of LSVT. The presence of LSVTs is associated neither with clinical variables nor with sacroiliitis. References [1]Heaps BM, Feingold JD, Swartwout E, et al. Lumbosacral Transitional Vertebrae Predict Inferior Patient-Reported Outcomes After Hip Arthroscopy. Am J Sports Med . 2020;48(13):3272-3279 [2]Matson DM, Maccormick LM, Sembrano JN, Polly DW. Sacral Dysmorphism and Lumbosacral Transitional Vertebrae (LSTV) Review. Int J Spine Surg . 2020;14(Suppl 1):14-19. Published 2020 [3]Carvajal Alegria G, Voirin-Hertz M, Garrigues F, et al. Association of lumbosacral transitional vertebra and sacroiliitis in patients with inflammatory back pain suggesting axial spondyloarthritis. Rheumatology (Oxford ). 2020;59(7):1679-1683. Disclosure of Interests None declared